linux/drivers/hwmon/adt7410.c
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   1/*
   2 * adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
   3 *       monitoring
   4 * This driver handles the ADT7410 and compatible digital temperature sensors.
   5 * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
   6 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
   7 * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24#include <linux/module.h>
  25#include <linux/init.h>
  26#include <linux/slab.h>
  27#include <linux/jiffies.h>
  28#include <linux/i2c.h>
  29#include <linux/hwmon.h>
  30#include <linux/hwmon-sysfs.h>
  31#include <linux/err.h>
  32#include <linux/mutex.h>
  33#include <linux/delay.h>
  34
  35/*
  36 * ADT7410 registers definition
  37 */
  38
  39#define ADT7410_TEMPERATURE             0
  40#define ADT7410_STATUS                  2
  41#define ADT7410_CONFIG                  3
  42#define ADT7410_T_ALARM_HIGH            4
  43#define ADT7410_T_ALARM_LOW             6
  44#define ADT7410_T_CRIT                  8
  45#define ADT7410_T_HYST                  0xA
  46
  47/*
  48 * ADT7410 status
  49 */
  50#define ADT7410_STAT_T_LOW              (1 << 4)
  51#define ADT7410_STAT_T_HIGH             (1 << 5)
  52#define ADT7410_STAT_T_CRIT             (1 << 6)
  53#define ADT7410_STAT_NOT_RDY            (1 << 7)
  54
  55/*
  56 * ADT7410 config
  57 */
  58#define ADT7410_FAULT_QUEUE_MASK        (1 << 0 | 1 << 1)
  59#define ADT7410_CT_POLARITY             (1 << 2)
  60#define ADT7410_INT_POLARITY            (1 << 3)
  61#define ADT7410_EVENT_MODE              (1 << 4)
  62#define ADT7410_MODE_MASK               (1 << 5 | 1 << 6)
  63#define ADT7410_FULL                    (0 << 5 | 0 << 6)
  64#define ADT7410_PD                      (1 << 5 | 1 << 6)
  65#define ADT7410_RESOLUTION              (1 << 7)
  66
  67/*
  68 * ADT7410 masks
  69 */
  70#define ADT7410_T13_VALUE_MASK                  0xFFF8
  71#define ADT7410_T_HYST_MASK                     0xF
  72
  73/* straight from the datasheet */
  74#define ADT7410_TEMP_MIN (-55000)
  75#define ADT7410_TEMP_MAX 150000
  76
  77enum adt7410_type {             /* keep sorted in alphabetical order */
  78        adt7410,
  79};
  80
  81static const u8 ADT7410_REG_TEMP[4] = {
  82        ADT7410_TEMPERATURE,            /* input */
  83        ADT7410_T_ALARM_HIGH,           /* high */
  84        ADT7410_T_ALARM_LOW,            /* low */
  85        ADT7410_T_CRIT,                 /* critical */
  86};
  87
  88/* Each client has this additional data */
  89struct adt7410_data {
  90        struct device           *hwmon_dev;
  91        struct mutex            update_lock;
  92        u8                      config;
  93        u8                      oldconfig;
  94        bool                    valid;          /* true if registers valid */
  95        unsigned long           last_updated;   /* In jiffies */
  96        s16                     temp[4];        /* Register values,
  97                                                   0 = input
  98                                                   1 = high
  99                                                   2 = low
 100                                                   3 = critical */
 101        u8                      hyst;           /* hysteresis offset */
 102};
 103
 104/*
 105 * adt7410 register access by I2C
 106 */
 107static int adt7410_temp_ready(struct i2c_client *client)
 108{
 109        int i, status;
 110
 111        for (i = 0; i < 6; i++) {
 112                status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 113                if (status < 0)
 114                        return status;
 115                if (!(status & ADT7410_STAT_NOT_RDY))
 116                        return 0;
 117                msleep(60);
 118        }
 119        return -ETIMEDOUT;
 120}
 121
 122static struct adt7410_data *adt7410_update_device(struct device *dev)
 123{
 124        struct i2c_client *client = to_i2c_client(dev);
 125        struct adt7410_data *data = i2c_get_clientdata(client);
 126        struct adt7410_data *ret = data;
 127        mutex_lock(&data->update_lock);
 128
 129        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
 130            || !data->valid) {
 131                int i, status;
 132
 133                dev_dbg(&client->dev, "Starting update\n");
 134
 135                status = adt7410_temp_ready(client); /* check for new value */
 136                if (unlikely(status)) {
 137                        ret = ERR_PTR(status);
 138                        goto abort;
 139                }
 140                for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
 141                        status = i2c_smbus_read_word_swapped(client,
 142                                                        ADT7410_REG_TEMP[i]);
 143                        if (unlikely(status < 0)) {
 144                                dev_dbg(dev,
 145                                        "Failed to read value: reg %d, error %d\n",
 146                                        ADT7410_REG_TEMP[i], status);
 147                                ret = ERR_PTR(status);
 148                                goto abort;
 149                        }
 150                        data->temp[i] = status;
 151                }
 152                status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
 153                if (unlikely(status < 0)) {
 154                        dev_dbg(dev,
 155                                "Failed to read value: reg %d, error %d\n",
 156                                ADT7410_T_HYST, status);
 157                        ret = ERR_PTR(status);
 158                        goto abort;
 159                }
 160                data->hyst = status;
 161                data->last_updated = jiffies;
 162                data->valid = true;
 163        }
 164
 165abort:
 166        mutex_unlock(&data->update_lock);
 167        return ret;
 168}
 169
 170static s16 ADT7410_TEMP_TO_REG(long temp)
 171{
 172        return DIV_ROUND_CLOSEST(clamp_val(temp, ADT7410_TEMP_MIN,
 173                                           ADT7410_TEMP_MAX) * 128, 1000);
 174}
 175
 176static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
 177{
 178        /* in 13 bit mode, bits 0-2 are status flags - mask them out */
 179        if (!(data->config & ADT7410_RESOLUTION))
 180                reg &= ADT7410_T13_VALUE_MASK;
 181        /*
 182         * temperature is stored in twos complement format, in steps of
 183         * 1/128°C
 184         */
 185        return DIV_ROUND_CLOSEST(reg * 1000, 128);
 186}
 187
 188/*-----------------------------------------------------------------------*/
 189
 190/* sysfs attributes for hwmon */
 191
 192static ssize_t adt7410_show_temp(struct device *dev,
 193                                 struct device_attribute *da, char *buf)
 194{
 195        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 196        struct adt7410_data *data = adt7410_update_device(dev);
 197
 198        if (IS_ERR(data))
 199                return PTR_ERR(data);
 200
 201        return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
 202                       data->temp[attr->index]));
 203}
 204
 205static ssize_t adt7410_set_temp(struct device *dev,
 206                                struct device_attribute *da,
 207                                const char *buf, size_t count)
 208{
 209        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 210        struct i2c_client *client = to_i2c_client(dev);
 211        struct adt7410_data *data = i2c_get_clientdata(client);
 212        int nr = attr->index;
 213        long temp;
 214        int ret;
 215
 216        ret = kstrtol(buf, 10, &temp);
 217        if (ret)
 218                return ret;
 219
 220        mutex_lock(&data->update_lock);
 221        data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
 222        ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
 223                                           data->temp[nr]);
 224        if (ret)
 225                count = ret;
 226        mutex_unlock(&data->update_lock);
 227        return count;
 228}
 229
 230static ssize_t adt7410_show_t_hyst(struct device *dev,
 231                                   struct device_attribute *da,
 232                                   char *buf)
 233{
 234        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 235        struct adt7410_data *data;
 236        int nr = attr->index;
 237        int hyst;
 238
 239        data = adt7410_update_device(dev);
 240        if (IS_ERR(data))
 241                return PTR_ERR(data);
 242        hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;
 243
 244        /*
 245         * hysteresis is stored as a 4 bit offset in the device, convert it
 246         * to an absolute value
 247         */
 248        if (nr == 2)    /* min has positive offset, others have negative */
 249                hyst = -hyst;
 250        return sprintf(buf, "%d\n",
 251                       ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
 252}
 253
 254static ssize_t adt7410_set_t_hyst(struct device *dev,
 255                                  struct device_attribute *da,
 256                                  const char *buf, size_t count)
 257{
 258        struct i2c_client *client = to_i2c_client(dev);
 259        struct adt7410_data *data = i2c_get_clientdata(client);
 260        int limit, ret;
 261        long hyst;
 262
 263        ret = kstrtol(buf, 10, &hyst);
 264        if (ret)
 265                return ret;
 266        /* convert absolute hysteresis value to a 4 bit delta value */
 267        limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
 268        hyst = clamp_val(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
 269        data->hyst = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000), 0,
 270                               ADT7410_T_HYST_MASK);
 271        ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
 272        if (ret)
 273                return ret;
 274
 275        return count;
 276}
 277
 278static ssize_t adt7410_show_alarm(struct device *dev,
 279                                  struct device_attribute *da,
 280                                  char *buf)
 281{
 282        struct i2c_client *client = to_i2c_client(dev);
 283        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 284        int ret;
 285
 286        ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
 287        if (ret < 0)
 288                return ret;
 289
 290        return sprintf(buf, "%d\n", !!(ret & attr->index));
 291}
 292
 293static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
 294static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
 295                          adt7410_show_temp, adt7410_set_temp, 1);
 296static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
 297                          adt7410_show_temp, adt7410_set_temp, 2);
 298static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
 299                          adt7410_show_temp, adt7410_set_temp, 3);
 300static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
 301                          adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
 302static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
 303                          adt7410_show_t_hyst, NULL, 2);
 304static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
 305                          adt7410_show_t_hyst, NULL, 3);
 306static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
 307                          NULL, ADT7410_STAT_T_LOW);
 308static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
 309                          NULL, ADT7410_STAT_T_HIGH);
 310static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
 311                          NULL, ADT7410_STAT_T_CRIT);
 312
 313static struct attribute *adt7410_attributes[] = {
 314        &sensor_dev_attr_temp1_input.dev_attr.attr,
 315        &sensor_dev_attr_temp1_max.dev_attr.attr,
 316        &sensor_dev_attr_temp1_min.dev_attr.attr,
 317        &sensor_dev_attr_temp1_crit.dev_attr.attr,
 318        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 319        &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
 320        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 321        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
 322        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 323        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 324        NULL
 325};
 326
 327static const struct attribute_group adt7410_group = {
 328        .attrs = adt7410_attributes,
 329};
 330
 331/*-----------------------------------------------------------------------*/
 332
 333/* device probe and removal */
 334
 335static int adt7410_probe(struct i2c_client *client,
 336                         const struct i2c_device_id *id)
 337{
 338        struct adt7410_data *data;
 339        int ret;
 340
 341        if (!i2c_check_functionality(client->adapter,
 342                        I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 343                return -ENODEV;
 344
 345        data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
 346                            GFP_KERNEL);
 347        if (!data)
 348                return -ENOMEM;
 349
 350        i2c_set_clientdata(client, data);
 351        mutex_init(&data->update_lock);
 352
 353        /* configure as specified */
 354        ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
 355        if (ret < 0) {
 356                dev_dbg(&client->dev, "Can't read config? %d\n", ret);
 357                return ret;
 358        }
 359        data->oldconfig = ret;
 360        /*
 361         * Set to 16 bit resolution, continous conversion and comparator mode.
 362         */
 363        ret &= ~ADT7410_MODE_MASK;
 364        data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |
 365                        ADT7410_EVENT_MODE;
 366        if (data->config != data->oldconfig) {
 367                ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 368                                                data->config);
 369                if (ret)
 370                        return ret;
 371        }
 372        dev_dbg(&client->dev, "Config %02x\n", data->config);
 373
 374        /* Register sysfs hooks */
 375        ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
 376        if (ret)
 377                goto exit_restore;
 378
 379        data->hwmon_dev = hwmon_device_register(&client->dev);
 380        if (IS_ERR(data->hwmon_dev)) {
 381                ret = PTR_ERR(data->hwmon_dev);
 382                goto exit_remove;
 383        }
 384
 385        dev_info(&client->dev, "sensor '%s'\n", client->name);
 386
 387        return 0;
 388
 389exit_remove:
 390        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 391exit_restore:
 392        i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
 393        return ret;
 394}
 395
 396static int adt7410_remove(struct i2c_client *client)
 397{
 398        struct adt7410_data *data = i2c_get_clientdata(client);
 399
 400        hwmon_device_unregister(data->hwmon_dev);
 401        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
 402        if (data->oldconfig != data->config)
 403                i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 404                                          data->oldconfig);
 405        return 0;
 406}
 407
 408static const struct i2c_device_id adt7410_ids[] = {
 409        { "adt7410", adt7410, },
 410        { "adt7420", adt7410, },
 411        { /* LIST END */ }
 412};
 413MODULE_DEVICE_TABLE(i2c, adt7410_ids);
 414
 415#ifdef CONFIG_PM_SLEEP
 416static int adt7410_suspend(struct device *dev)
 417{
 418        int ret;
 419        struct i2c_client *client = to_i2c_client(dev);
 420        struct adt7410_data *data = i2c_get_clientdata(client);
 421
 422        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
 423                                        data->config | ADT7410_PD);
 424        return ret;
 425}
 426
 427static int adt7410_resume(struct device *dev)
 428{
 429        int ret;
 430        struct i2c_client *client = to_i2c_client(dev);
 431        struct adt7410_data *data = i2c_get_clientdata(client);
 432
 433        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
 434        return ret;
 435}
 436
 437static SIMPLE_DEV_PM_OPS(adt7410_dev_pm_ops, adt7410_suspend, adt7410_resume);
 438
 439#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
 440#else
 441#define ADT7410_DEV_PM_OPS NULL
 442#endif /* CONFIG_PM */
 443
 444static struct i2c_driver adt7410_driver = {
 445        .class          = I2C_CLASS_HWMON,
 446        .driver = {
 447                .name   = "adt7410",
 448                .pm     = ADT7410_DEV_PM_OPS,
 449        },
 450        .probe          = adt7410_probe,
 451        .remove         = adt7410_remove,
 452        .id_table       = adt7410_ids,
 453        .address_list   = I2C_ADDRS(0x48, 0x49, 0x4a, 0x4b),
 454};
 455
 456module_i2c_driver(adt7410_driver);
 457
 458MODULE_AUTHOR("Hartmut Knaack");
 459MODULE_DESCRIPTION("ADT7410/ADT7420 driver");
 460MODULE_LICENSE("GPL");
 461
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